Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): New insights from increased taxon sampling

Phylogenetic relationships among higher clades of pulmonate gastropods are reconstructed based on a data set including one nuclear marker (complete ribosomal 18S) and two mitochondrial markers (partial ribosomal 16S and Cytochrome oxidase I) for a total of 96 species. Sequences for 66 of these species are new to science, with a special emphasis on sampling the Ellobiidae, Onchidiidae, and Veronicellidae. Important results include the monophyly of Systellommatophora (Onchidiidae and Veronicellidae) as well as the monophyly of Ellobiidae (including Trimusculus, Otina, and Smeagol). Relationships within Ellobiidae, Onchidiidae, and Veronicellidae are evaluated here for the first time using molecular data. Present results are compared with those from the recent literature, and the current knowledge of phylogenetic relationships among pulmonate gastropods is reviewed: despite many efforts, deep nodes are still uncertain. Identification uncertainties about early fossils of pulmonates are reviewed. Impacts of those phylogenetic and fossil record uncertainties on our understanding of the macro-evolutionary history of pulmonates, especially transitions between aquatic and terrestrial habitats, are discussed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Sequences of 16S, CoI, and 18S newly added for 65 species of pulmonate gastropods. ► Monophyly of Systellommatophora (Onchidiidae and Veronicellidae). ► Monophyly of Ellobiidae (including Trimusculus, Otina, and Smeagol). ► Deep nodes are still uncertain. ► Macro-evolutionary history of pulmonates is reviewed.